Abstract

                                The subject of uptake of nutrients by crops has received intensive and extensive treatment in recent years. Analysis of soils, before and after the growth of crops, may give information regarding the uptake of nutrients by these crops as influenced by their root cation exchange capacities and soil properties. An attempt was made to study the role of root cation exchange capacity and soil properties on the removal of nutrients, with special reference to phosphorus, by two crops viz., ragi and daincha from two major types of South Indian soils, namely red and black soils, and also the availability of different phosphatic fertilisers in these soils as indicated by Neubauer test. The results of this study are reported in this paper. The availability of nutrients particularly phosphorus, both native and applied is known to be influenced by soil properties. Chapman (1936) indicated that acid nitrogenous fertilisers increased availability of phosphorus in calcareous soils. Joos and Black (.950) stated that the availability of rock phosphate was increased by highly acid nature of the soil. Bircm (1951) found that with increasing base saturation of the soil, the availability of phosphorus became poor.

Key words :